Examples, solutions, and videos to help Grade 3 students learn how to analyze different rectangles and reason about their area.
Common Core Standards: 3.MD.5, 3.MD.6, 3.MD.7a, 3.MD.7b, 3.MD.7d
Mario plans to completely cover his 8-inch by 6-inch cardboard with square-inch tiles. He has 42 square-inch tiles. How many more square-inch tiles does Mario need to cover the cardboard without any gaps or overlap? Explain your answer.
Note: This problem reviews the concept of finding area. Students will likely solve by multiplying side lengths (shown above), having just practiced this strategy in 3–M4–Lesson 8.
How can we use the areas of 2 small rectangles that form a longer rectangle to find the area of the longer rectangle?
Add the areas of the smaller rectangles.
Lesson 9 Homework
Try the free Mathway calculator and
problem solver below to practice various math topics. Try the given examples, or type in your own
problem and check your answer with the step-by-step explanations.
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